Above: I found the first one on a DOS game site, maybe check one of those?
As said, Steam. Maybe pick up invisible war as well, since they come bundled.
I play Minecraft, and love it. I have only played the first level in Deus Ex, and I love it as well. Minecraft has more 'game time' if you can call it such in the game, while Deus Ex has numerous different scenerios, and ways of doing things, and is half the price; I've HEARD the original averages 20 hours per one playthrough, I don't know the accuracy of such a statement. I enjoyed the little time I played in Deus Ex more then in Minecraft. They are two of the finest games I have ever played. Get both, $31 is a great price for one decent game, you would be buying to magnificent ones.